/**
 * 
 * @desc 删除字符串首尾空格或特定字符
 * @param  {String} str 
 * @param  {String|Array} chars 
 * @return {String} 
 */
function trim(str, chars) {
    if (!str) return;
    string = str.toString();
    if (!chars) {
        return string.replace(/^\s+|\s+$/g, "");
    } else if (typeof chars === "string") {
        var arrStr = string.split("");
        var arr = [];
        for (var i = 0; i < arrStr.length; i++) {
            if (arrStr[i] !== chars) arr.push(arrStr[i]);
        }
        return arr.join("");
    } else if (chars instanceof Array) {
        var arrStr = string.split("");
        for (var i = 0; i < chars.length; i++) {
            for (var j = 0; j < arrStr.length; j++) {
                if (chars[i] === arrStr[j]) arrStr.splice(j, 1);
            }
        }
        return arrStr.join("");
    }
    return string;
}

module.exports = trim;